Counterterms, Holonomy and Supersymmetry (original) (raw)
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General form of string corrections to supersymmetry transformation in D=10, N=1 supergravity
Physics Letters B, 1987
We present the O(a' 3) heterotic string corrections to the supersymmetry transformation rules of D= 10, N= I supergravity multiplet, which satisfy the on-shell closure of supersymmetry. We also generalize this result to higher orders in a', assuming a natural form of the leading O (o~'") heterotic string corrections to the effective action of the supergravity multiplet. We find no modification to the Killing spinor equations for the gravitino and dilatino at O(a' 5) or higher, whenever fermionic condensates are absent. 1. Introduction. One of the most important features of ten-dimensional string theories [ 1 ] is the possibility of non-trivial (chiral) compactification into four-dimensional space-time (D=4) in the point field theory limit. In particular, in the heterotic string theory with the gauge group Es × E8 [2], the compactification on Calabi-Yau manifolds with SU(3) holonomy gives rise to D= 4, N= 1 surviving supersymmetry with the grand unification group E 6 [31. The analysis in ref. [ 3 ] was based on the tree-level O(c~') correction to the D= 10, N= 1 supergravity, that arise from the Green-Schwarz anomaly cancellation mechanism [4]. Recently, higher order corrections have been obtained by tree-level string amplitude calculations in D= 10 [5,6], and by amodel fl-function calculations in D = 2 [ 7 ]. Essential agreement between these two kinds of calculations has been found up to O(a'4). It is also claimed that the Calabi-Yau manifold is the solution of the treelevel field equations in D = 10 to all orders in ce' [ 8 ]. The original motivation [3] of considering the Calabi-Yau manifold for surviving supersymmetry, however, has become obscure, because the covariant supersymmetry transformation rules in D = 10 with higher order corrections in or' needed for Killing spi
Constraints from F and D supersymmetry breaking in general supergravity theories
Fortschritte der Physik, 2008
We study the conditions under which a generic supergravity model involving chiral and vector multiplets can admit vacua with spontaneously broken supersymmetry and realistic cosmological constant. We find that the existence of such viable vacua implies some constraints involving the curvature tensor of the scalar geometry and the charge and mass matrices of the vector fields, and also that the vector of F and D auxiliary fields defining the Goldstino direction is constrained to lie within a certain domain. We illustrate the relevance of these results through some examples and also discuss the implications of our general results on the dynamics of moduli fields in string models. This contribution is based on [1–3].
String and M-theory deformations of manifolds with special holonomy
Journal of High Energy Physics, 2005
The R 4-type corrections to ten and eleven dimensional supergravity required by string and M-theory imply corrections to supersymmetric supergravity compactifications on manifolds of special holonomy, which deform the metric away from special holonomy. Nevertheless, in many such cases, including Calabi-Yau compactifications of string theory and G 2-compactifications of M-theory, it has been shown that because of associated corrections to the supersymmetry transformation rules, the deformation remains supersymmetric. Here, we consider Spin(7) compactifications of string theory, showing that once again supersymmetry survives, despite the loss of Spin(7) holonomy in the deformed background. We also consider the deformations of Spin(7) backgrounds in M-theory, showing that supersymmetry is also maintained in that case. Finally, we consider the intrinsically M-theoretic case of compactifications on 10-manifolds of SU(5) holonomy. We obtain the corrected solutions, and show that these too are supersymmetric.
String corrections to supergravity theories
2003
In this thesis, we study the leading quantum corrections to supergravity theories in four dimensions, given by the fourth power of the Riemann tensor ( R4 ). We write, in four-dimensional superspace, the N = 1 minimal action which contains the fourth power of the Weyl tensor with a coupling constant. Starting from the superspace action, we fully compute the
Nonminimal string corrections and supergravity
Physical Review D, 2006
We reconsider the well-known issue of string corrections to Supergravity theory. Our treatment is carried out to second order in the string slope parameter. We establish a procedure for solving the Bianchi identities in the non minimal case, and we solve a long standing problem in the perturbative expansion of D=10, N=1 string corrected Supergravity, obtaining the H sector tensors, torsions and curvatures.
String defects, supersymmetry and the Swampland
Journal of High Energy Physics, 2020
Recently, Kim, Shiu and Vafa proposed general consistency conditions for six dimensional supergravity theories with minimal supersymmetry coming from couplings to strings. We test them in explicit perturbative orientifold models in order to unravel the microscopic origin of these constraints. Based on the perturbative data, we conjecture the existence of null charges Q∙Q = 0 for any six-dimensional theory with at least one tensor multiplet, coupling to string defects of charge Q. We then include the new constraint to exclude some six-dimensional supersymmetric anomaly-free examples that have currently no string or F-theory realization. We also investigate the constraints from the couplings to string defects in case where supersymmetry is broken in tachyon free vacua, containing non-BPS configurations of brane supersymmetry breaking type, where the breaking is localized on antibranes. In this case, some conditions have naturally to be changed or relaxed whenever the string defects ex...
Inclusion of Yang–Mills fields in string corrected supergravity
Physics Letters B, 2008
We consistently incorporate Yang Mills matter fields into string corrected (deformed), D=10, N=1 Supergravity. We solve the Bianchi identities within the framework of the modified beta function favored constraints to second order in the string slope parameter γ also including the Yang Mills fields. In the torsion, curvature and H sectors we find that a consistent solution is readily obtained with a Yang Mills modified supercurrent A abc. We find a solution in the F sector following our previously developed method.
We show how to construct chiral tachyon-free perturbative orientifold models, where supersymmetry is broken at the string scale on a collection of branes while, to lowest order, the bulk and the other branes are supersymmetric. In higher orders, supersymmetry breaking is mediated to the remaining sectors, but is suppressed by the size of the transverse space or by the distance from the brane where supersymmetry breaking primarily occurred. This setting is of interest for orbifold models with discrete torsion, and is of direct relevance for low-scale string models. It can guarantee the stability of the gauge hierarchy against gravitational radiative corrections, allowing an almost exact supergravity a millimeter away from a non-supersymmetric world.
The spacetime supersymmetric formulation of the string
Physics Reports, 1990
The superparticle in background supergravitational 1. Introduction 223 fields 258 2. Classical superparticles and the twistor transform 225 3. The superstring in curved superspace 269 2.1. Constrained dynamics of massless particles 225 3.1. The superstring action 270 2.2. A first look at the superparticle 228 3.2. The constraints in "flat" superspace 276 2.3. Superspace 229 3.3. The first-class constraints in curved space 277 2.4. Constrained dynamics of the superparticle 234 4. Recent developments 280 2.5. The superparticle in background Yang-Mills fields 239 Appendix A. Gamma matrices 282 2.6. Constraint equations and the super-Yang-Mills equa-Al. The Dirac algebra 282 tions of motion 247 A.2. Fierz identities 284 2.7. The ten-dimensional twistor transform 252 References 286
Probing naked singularities in non-supersymmetric string vacua
Journal of High Energy Physics, 2001
We present a detailed analysis of non-supersymmetric spacetime varying string vacua which can lead to an exponential hierarchy between the electroweak and the gravitational scales. In particular, we identify a limit in which these vacua can be interpreted as supersymmetric vacua of F-theory. Furthermore, we study the properties of these solutions as seen by D7-brane probes and establish a non-supersymmetric analogue of the enhançon mechanism.